This invention relates to the configuration of an HVAC communication network so as to facilitate communications between devices connected to the network. In particular this invention relates to how a device is identified and assigned a network address within the communication network.
The use of a communication network to convey HVAC control information over a common communication bus to devices connected to the bus is well known. Such networks are often used when one wishes to implement a hierarchical control of several heating or cooling devices. A central or master controller in such a hierarchical control will normally communicate with the devices connected thereto over a common control bus. In order to do so, the hierarchical control needs to be able to identify each device connected to the bus so that the particular device can be addressed by the central or master controller.
U.S. Pat. No. 5,818,347 entitled xe2x80x9cIdentification of HVAC Systems in a Communication Networkxe2x80x9d discloses a particular approach to assigning a network identification to an HVAC device. The device is assigned a network identification or network address by a hand held device which communicates with the HVAC device so as to thereby transfer the network identification to the HVAC device. The above system however requires that the network controller know in advance the network identification assigned to the HVAC device.
Other systems which identify an HVAC device within a communication network include providing buttons on either an HVAC zone controller or on a wall mounted device connected to the zone controller. Depression of such a button is interpreted as a signal over the network that the zone controller awaits the assignment of a network address. The technician performing such a network address assignment must usually walk from wherever the zone controller is located to a location where either a master controller or a computer is located that will assign a network address assignment to the zone controller. The person uses information as to the location of the zone controller to provide the network address to the master controller that will thereafter assign a network address to the zone controller.
It is an object of the invention to provide a system and method for quickly, easily and reliably assigning a network address to a zone controller or other HVAC network device.
An HVAC communication network includes a network controller node coupled to one or more down stream nodes by a distributed communication bus. Each down stream node preferably consists of some type of HVAC network device. At least some of these devices are provided with preprogrammed tags having tag identifications which can be read by a read/write device. The tag is preferably a radio frequency identification (RFID) tag. The tag identification for each device is stored in a nonvolatile memory within the HVAC network device. This is preferably done at some point during the manufacture of the network device.
In accordance with the invention, a technician will use a hand held device capable of reading the RFID tags of the HVAC network devices that have been connected to the distributed communication bus. The RFID tag on a particular HVAC network device will transmit its tag identification to the hand held device when the hand held device is in the vicinity of the particular device. The technician will access a floor plan identifying locations in the building where the HVAC network devices have been installed. This location information is used to identify a particular network address that is to be assigned to the HVAC network device in that particular location. This is preferably accomplished by accessing a data base that includes network addresses for particular locations. The thus identified network address along with the tag identification is transmitted to the network controller for the communication network. The network controller will transmit a configuration message over the communication bus that will include the tag identification as well as the desired network address. The HVAC network device having the matching tag identification will respond to the configuration message from the network controller so as to thereby allow the desired network address to be downloaded to the particular HVAC network device. Once the network address for the particular network device node has been established, then additional messages addressed to the particular HVAC network device can occur without use of the tag identification.